Image forming apparatus,  molded resin product for use with the image forming apparatus, and cartridge

ABSTRACT

A molded resin product for use with an image forming apparatus includes: a base portion formed of a resin material; a positioning portion provided on the base portion; and a movable member formed by injection molding so as to be movable relative to the base portion. When the molded resin product is connected to a connection part, the positioning portion positions the molded resin product and the connection part relative to each other, and the movable member is contactable to a contact portion of the connection part.

FIELD OF THE INVENTION AND RELATED ART

The present invention relates to an image forming apparatus, a moldedresin product for use with the image forming apparatus, and a cartridge.

In the case where a plastic product having a complicated structure wasmanufactured in a conventional constitution, many species of parts wereseparately prepared and were assembled and manufactured in separationsteps. Therefore, in order to not only simplify part molding steps butalso facilitate assembly, an integrally molding method and an integrallymolded product have been proposed (Japanese Laid-Open Patent Application(JP-A) 2000-015656). In this method, a sheet of a rotatable member and abearing are connected and integrally molded with each other so as to beinseparable from each other, and thereafter the sheet is moved to bepredetermined position and is fixed. In general, in an injection moldingof plastics, a gap (spacing) corresponding to a thickness of a metalmold is inevitably formed, and therefore when a cavity of the metal moldis used as a bearing as it is and the rotatable member is rotated, adegree of rotation wobbling is large and thus the molded product cannotbe put into practical use. Therefore, an example in which a stablerotation function with less wobbling is ensured by moving the sheetpositioned in the cavity during the molding to a bearing portion along aslit, and the number of steps of manufacturing and assembling manyspecies of parts is reduced has been proposed.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, there is provided amolded resin product for use with an image forming apparatus,comprising: a base portion formed of a resin material; a positioningportion provided on the base portion; and a movable member formed byinjection molding so as to be movable relative to the base portion,wherein when the molded resin product is connected to a connection part,the positioning portion positions the molded resin product and theconnection part relative to each other, and the movable member iscontactable to a contact portion of the connection part.

According to another aspect of the present invention, there is provideda cartridge detachably mountable to an image forming apparatus,comprising: a molded resin product including a base portion formed of aresin material, a positioning portion provided on the base portion, anda movable member formed by injection molding so as to be movablerelative to the base portion; and a connection part connectable to themolded resin product, wherein when the molded resin product is connectedto the connection part, the positioning portion positions the moldedresin product and the connection part relative to each other, and themovable member is contactable to a contact portion of the connectionpart.

These and other objects, features and advantages of the presentinvention will become more apparent upon a consideration of thefollowing description of the preferred embodiments of the presentinvention taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a cartridge according to Embodiment 1 ofthe present invention.

FIG. 2 is a sectional view of an image forming apparatus in Embodiment1.

FIG. 3 is a sectional view of a developing unit in Embodiment 1.

FIG. 4 is a perspective view of the developing unit in Embodiment 1.

FIG. 5 is a sectional view of the developing unit in Embodiment 1.

FIG. 6 is an enlarged perspective view showing a part of the developingunit in Embodiment 1.

FIG. 7 is a perspective view of a bearing in Embodiment 1.

In FIG. 8, (a) and (b) are perspective views each showing partsconstituting the bearing in Embodiment 1.

In FIG. 9, (a) and (b) are schematic views for illustrating a bearingforming method in Embodiment 1.

In FIG. 10, (a) and (b) are enlarged views each showing a part of abearing in Embodiment 2 of the present invention.

In FIG. 11, (a) to (c) are enlarged views each showing a part of adeveloping unit in Embodiment 2.

FIG. 12 is a perspective view of the bearing in Embodiment 2.

In FIG. 13, (a) and (b) are perspective views each showing partsconstituting the bearing in Embodiment 2, and (c) is a sectional viewshowing the parts constituting the bearing in Embodiment 2.

In FIG. 14, (a) and (b) are schematic views for illustrating a bearingforming method in Embodiment 2.

In FIG. 15, (a) to (c) are enlarged views each showing a part of thebearing in Embodiment 2.

FIG. 16 is a perspective view of a bearing in Embodiment 3.

In FIG. 17, (a) to (c) are perspective views each showing a developingunit or parts thereof in Embodiment 3.

FIG. 18 is a perspective view of the bearing in Embodiment 3.

In FIG. 19, (a) and (b) are perspective views each showing a secondframe in Embodiment 3.

FIG. 20 is a sectional view showing a part of the second frame inEmbodiment 3.

In FIG. 21, (a) and (b) are sectional views each showing a part of thedeveloping unit in Embodiment 3.

FIG. 22 is an illustration showing the part of the developing unit inEmbodiment 3.

In FIG. 23, (a) and (b) are sectional views each showing the part of thedeveloping unit in Embodiment 3.

FIG. 24 is an illustration of an assembling structure of the developingunit in Embodiment 3.

In FIG. 25, (a) to (c) are perspective views each showing anotherexample of a movable member in Embodiment 3.

FIG. 26 is a perspective view showing an example of a movable member inanother embodiment.

DESCRIPTION OF THE EMBODIMENTS

Hereinbelow, embodiments of the present invention will be specificallydescribed with reference to the drawings. However, dimensions, materialsand shapes of constituent elements and their relative arrangements andthe like described in the following embodiments should be changedappropriately depending on structures and various conditions ofapparatuses (devices) to which the present invention is applied, andtherefore, the scope of the present invention is not intended to belimited to the following embodiments.

The present invention relates to an electrophotographic image formingapparatus, a process cartridge and a molded resin product for use withthe image forming apparatus. The image forming apparatus forms an imageon a recording material by using an image forming process such as anelectrophotographic process or an ink jet recording process. Examples ofthe image forming apparatus may include an electrophotographic copyingmachine, an electrophotographic printer (such as a laser beam printer oran LED printer), a facsimile machine, and a word processor. Further,also an image forming apparatus of an ink jet recording type in whichrecording is effected by ejecting ink through ejection outlets of arecording head on the basis of image information is included in thescope of the present invention.

Embodiment 1 (Image Forming Apparatus Using Bearing)

As Embodiment 1, the case where a molded resin product, according to thepresent invention, formed by multicolor molding is used for a cartridgedetachably mountable to the image forming apparatus will be describedwith reference to FIGS. 1-6. In this embodiment, a two-color-moldedbearing including an electrode portion will be described as an example.

In this embodiment, as the image forming apparatus, theelectrophotographic image forming apparatus will be described as anexample. A cartridge is a generic name for a drum cartridge forsupporting an electrophotographic photosensitive drum, a developingcartridge for supporting a developing means and a process cartridgeprepared by integrally assembling the electrophotographic photosensitivedrum and a process means into a cartridge (unit). The process means actson the electrophotographic photosensitive drum, and examples thereof mayinclude not only a charging means, the developing means, the cleaningmeans and the like, which act on the electrophotographic photosensitivedrum, but also an application roller for applying a toner onto a tonercarrying member, a remaining toner amount detecting means and the like.The electrophotographic photosensitive drum and the process meanscorrespond to parts (components) for effecting image formation.

First, with reference to FIGS. 1 and 2, structures of a cartridge Aincluding a developing unit according to the present invention and animage forming apparatus main assembly B to which the cartridge A isdetachably mountable will be described. FIG. 1 is a sectional view ofthe cartridge A including the developing unit, and FIG. 2 is a sectionalview of the image forming apparatus main assembly B to which thecartridge A including the developing unit is detachably mountable.

(Structure of Cartridge)

The cartridge includes an image bearing member and the process meansactable on the image bearing member. As the process means, it ispossible to use, e.g., the charging means for electrically charging asurface of the image bearing member, the developing means for forming animage on the image bearing member, and the cleaning means for removingthe toner (containing a toner components, a carrier or the like)remaining on the image bearing member surface.

The cartridge A in this embodiment includes, as shown in FIG. 1, theimage bearing member (photosensitive drum 11) and its peripheral membersincluding a charging roller 12 as the charging means and a cleaner unit34 including an elastic cleaning blade 14 as the cleaning means.Further, the cartridge A includes a developing unit 38 including adeveloping roller 13, a developing blade 15 and a toner accommodatingcontainer 26 for accommodating the toner. The cartridge A is prepared byintegrally assembling the cleaner unit 34 and the developing unit 38into a cartridge (unit), and is constituted so as to be detachablymountable to the image forming apparatus main assembly B as shown inFIG. 2.

(Structure of Image Forming Apparatus)

The cartridge A is mounted in the image forming apparatus main assemblyB as shown in FIG. 2, and is used for image formation. The imageformation is effected by a process described below. First, a sheet S asa recording material (medium) such as paper is fed by a feeding roller 7from a sheet cassette 6 mounted at a lower portion of the apparatus. Insynchronism with the sheet feeding, a latent image is formed on thephotosensitive drum 11 by subjecting the photosensitive drum 11 toselective exposure to light. A toner supplied to the developing roller13 (toner carrying member) is carried in a thin layer on a surface ofthe developing roller 13. Then, by applying a developing bias (voltage)to the developing roller 13, the toner is supplied depending on thelatent image on the photosensitive drum 11, so that the latent image isdeveloped into a toner image. This toner image is transferred onto thefed sheet S by application of a bias voltage to a transfer roller 9. Thesheet S is fed to a fixing device 10, and thereafter the image is fixedon the sheet S and then the sheet S is discharged onto a sheet dischargeportion 3 provided at an upper portion of the apparatus.

Next, a structure of the developing unit 38 will be described withreference to FIGS. 3 and 4. FIG. 3 is a sectional view of the developingunit, and FIG. 4 is a perspective view of the developing unit.

(Developing Unit)

The developing unit 38 is constituted, as shown in FIGS. 3 and 4, by thedeveloping roller 13, the developing blade 15, a first frame 17, asecond frame 18 and bearings 20 and 25. In the developing unit 38, thebearings 20 and 25 rotatably support the developing roller 13. Further,the first frame 17 and the second frame 18 are combined, and thebearings 20 and 25 are disposed at longitudinal ends, so that the toneraccommodating container 26 for accommodating the toner is formed.

In the second frame 18, a remaining amount detecting member 24 ismounted. The remaining amount detecting member 24 is formed with anelectroconductive resin sheet, and the electroconductive resin sheet isfixed on the second frame 18 by bonding using a double-side tape,(thermal) welding or the like. In this embodiment, as theelectroconductive resin sheet, a resin sheet in which carbon black isdispersed is used. The remaining amount detecting member 24 may only berequired to have electroconductivity, and may also use a metal platesuch as a stainless steel plate.

In this embodiment, as shown in FIG. 4, of the bearings provided at thelongitudinal ends of the toner accommodating container 26, one is abearing 20 including an electrode. That is, the bearing 20 is connectedto a combined structure, of the first frame 17 and the second frame 18,which is a connection part. The bearing 20 includes a bearing portion22C and a movable member 21 including an electrode portion 21A.Incidentally, another bearing 25 is provided with a bearing membersimilar to the bearing portion 22C.

(Remaining Toner Amount Detecting Means)

An outline of the remaining toner amount detecting means will bedescribed with reference to FIG. 5. FIG. 5 is a sectional view of thecartridge for illustrating the remaining toner amount detecting means.

In the following, as a means for detecting a remaining toner amount, amethod in which detection of the remaining toner amount is made bymeasuring electrostatic capacity will be described. As a detecting meansfor the electrostatic capacity, the developing unit 38 is provided withthe remaining amount detecting member 24. The remaining amount detectingmember 24 is electrically connected via the electrode portion 21A to aninputting portion 50 of a remaining toner amount detecting device 51 inthe apparatus main assembly B.

When an AC voltage is applied to the developing roller 13, a currentcorresponding to the electrostatic capacity between the developingroller 13 and the remaining amount detecting member 24 is induced. Thiselectrostatic capacity changes depending on an amount of the toneroccupying a space between the developing roller 13 and the remainingamount detecting member 24. That is, a current value depending on thetoner amount is outputted from the remaining amount detecting member 24into the inputting portion 50 of the remaining toner amount detectingdevice 51 via the electrode portion 21A of the cartridge A. Then, on thebasis of the current value inputted into the remaining toner amountdetecting device 51, the toner amount between the developing roller 13and the remaining amount detecting member 24 can be calculated in realtime.

As shown in FIG. 5, the remaining amount detecting member 24 is providedon a bottom (surface) of the second frame 18, so that it is possible toknow a change in toner amount between the developing roller 13 and theremaining amount detecting member 24. In this embodiment, a constitutionin which a change in electrostatic capacity from the time when the tonerwas consumed to some extent until the toner was used up was measured andthen the remaining toner amount was notified to a user was employed.However, the present invention is not limited thereto, but the remainingamount detecting member 24 may also be disposed at any position since adetectable toner amount varies depending on the position of theremaining amount detecting member.

On the basis of a detection result of the toner amount obtained by theremaining toner amount detecting means, it is possible to prompt theuser to prepare a new process cartridge via, e.g., a display means.

(Structure of Contact of Remaining Amount Detecting Member)

The bearing including the electrode will be described with reference toFIG. 6. FIG. 6 is a perspective view showing the bearing and anelectrical contact of the remaining amount detecting member.

As shown in FIG. 6, the remaining amount detecting member 24 is mountedon the second frame 18 so that an electrical contact portion 24A of theremaining amount detecting member 24 projects in one of longitudinalsides of the toner accommodating container 26. Specifically, theelectrical contact portion 24A is provided so as to project into thebearing 20 connected to one of the first frame 17 (not shown) and thesecond frame 18. In this way, by providing the electrical contactportion 24A of the remaining amount detecting member 24 at an outside ofa portion where the toner is accommodated, the electrical contactportion 24A contacts the electrode portion 21A as a contact portion, andthus is electrically connected stably to the electrode portion 21A.

The electrode portion 21A is provided on the movable member 21 of thebearing 20, and when the process cartridge is mounted in the apparatusmain assembly B, a force is applied from the inputting portion 50 to themovable member 21, so that the movable member 21 is rotated in an arrowG direction and thus the electrode portion 21A is contactable to theelectrical contact portion 24A of the remaining amount detecting member24 with predetermined contact pressure. In this embodiment, a spring isused as an urging means 52, and when the cartridge A is mounted in amounting position of the apparatus main assembly B, the electricalcontact portion 24A is pressed by a force of about 120 gf exerted fromthe inputting portion 50 on the electrode portion 21A. As a result, theelectrical contact portion 24A of the remaining amount detecting member24 is electrically connected to the inputting portion 50 via theelectrode portion 21A of the bearing 20. The urging means may also be anelastic member such as a rubber.

(Structure of Bearing)

The bearing 20 will be specifically described with reference to FIG. 7.

In this embodiment, as shown in FIG. 7, the bearing 20 is constituted bythe movable member 21 and a supporting member 22. The supporting member22 includes a base portion 22A including an accommodating portion 22B,and a bearing portion 22C. The base portion 22A includes a bearingportion 22B1 at the accommodating portion 22B. On the other hand, themovable member 21 includes the electrode portion 21A and a shaft portion21B which is connected to the electrode portion 21A and which isrotatable relative to the base portion 22A in the arrow G direction. Theshaft portion 21B is supported by the bearing portion 22B1 via a gap(spacing) described later, so that the electrode portion 21A isrotatable relative to the base portion 22A.

In this embodiment, a constitution in which the accommodating portion22B is provided with the bearing portion 22B1 and thus the electrodeportion 21A cannot be disengaged (disconnected) from the bearing 20 isemployed. However, other than a constitution in which the accommodatingportion 22B is provided so as to surround the electrode portion 21Awithin a range not preventing motion of the electrode portion 21A as inthis embodiment, a constitution in which the accommodating portion 22Bis not provided may also be employed. In this case, a constitution inwhich two sides which extend in a direction crossing an axial directionof the shaft portion 21B and which are provided with at least thebearing portion 22B1 for supporting the shaft portion 21B of theelectrode portion 21A are provided on the base portion 22A may only berequired to be employed.

In addition, in this embodiment, in order to dispose the electricalcontact portion 24A of the remaining amount detecting member 24 at acontactable position with the electrode portion 21A when the movablemember 21 is rotated, the accommodating portion 22B is caused tofunction also as a positioning portion for positioning the supportingmember 22 and the second frame 18 relative to each other. Specifically,the electrical contact portion 24A is inserted into and engaged with theaccommodating portion 22B, so that the supporting member 22 and thesecond frame 18 of the toner accommodating container 26 are positionedrelative to each other. However, the present invention is not limited tothis constitution, but as a separate member from the accommodatingportion 22B, a positioning portion for disposing the electrical contactportion 24A of the remaining amount detecting member 24 and theelectrode portion 21A in a contactable position when the movable member21 is moved may also be provided.

When the bearing 20 in this embodiment is formed, in a conventionalmethod of forming the bearing by injection molding, a gap correspondingto a thickness of a metal mold is formed, and therefore in the casewhere the movable member 21 and the supporting member 22 are integrallymolded, the movable member 21 and the supporting member 22 was not ableto be disposed with high positional accuracy. On the other hand, in thecase where the movable member 21 and the supporting member 22 are formedas separate members, unless each of the movable member 21 and thesupporting member 22 are formed with high accuracy and these members areassembled with high positional accuracy, the movable member 21 and thesupporting member 22 were not able to be disposed with high positionalaccuracy. Therefore, in the following, a method of molding the movablemember 21 and the supporting member 22 will be described.

(Bearing Molding Method)

A molding method of the bearing 20 will be described with reference toFIGS. 8-10. In FIG. 8, (a) is a perspective view showing the supportingmember 22 of the bearing 20, and (b) is a perspective view showing themovable member 21. In FIG. 9, (a) is a front view of the bearing 20, and(b) is a sectional view, taken along A-A line in (a) of FIG. 9, showingthe neighborhood of the movable member 21 of the bearing 20.

Of the bearing 20, the supporting member 22 constituted by the baseportion 22A including the accommodating portion 22B and by the bearingportion 22C is formed early. During molding, the mold is opened towardat least one of an arrow E1 direction and an arrow E2 direction. In thisembodiment, the arrow E1 direction side is a cavity side (fixed side)and the arrow E2 direction side is a core side (movable side), and aconstitution in which the core is moved in the arrow E2 direction toopen the mold was employed. However, the arrow E1 direction side is thecore side (movable side) and the arrow E2 direction side is the cavityside (fixed side), and a constitution in which the core is moved in thearrow E1 direction to open the mold may also be employed.

The bearing portion 22B1 extends in a direction crossing the arrow E1 orE2 direction in which the mold opens, and constitutes an undercutportion where the bearing portion 22B1 cannot be parted in that state.Therefore, the undercut portion is formed by a slide core method inwhich after the bearing portion 22B1 is formed by a slide core, theslide core is pulled out from an inside of the bearing portion 22B1 byan angular pin with a parting operation, or by a like method.

Thereafter, the movable member 21 including the electrode portion 21Aand the shaft portion 21B as shown in (b) of FIG. 8 is integrally moldedwith the supporting member 22, so that the bearing 20 is formed. At thistime, molds 28A and 28B as shown in FIG. 9 are provided as separatemembers from a mold for the supporting member 22 in order to form ashape of the movable member 21. As a structure of the molds, a structurein which the core-side mold 28A is used as a mold common to thesupporting member 22 and the movable member 21 and only the cavity-sidemold is different from the core-side mold 28A may also be employed. Asshown in FIG. 9, the movable member 21 is molded by injecting anelectroconductive resin material into a space formed between theaccommodating portion 22B and the molds 28A and 28B. For that reason,the shaft portion 21B of the movable member 21 is formed in such a shapethat a shape of the bearing portion 22B1 is transferred. After themolding, a contact interface is formed between the bearing portion 22B1and the shaft portion 21B. Further, also other than the contactinterface between the bearing portion 22B1 and the shaft portion 21B, acontact interface is formed between the accommodating portion 22B andthe movable member 21 formed between the accommodating portion 22B andthe molds 28A and 28B. In this way, between the movable member 21 andthe supporting member 22, the interfaces are formed, so that theelectrode portion 21A is rotatable about the shaft portion 21B relativeto the base portion 22A of the supporting member 22.

In this embodiment, it is preferable that a resin material used as afirst resin material used for the supporting member 22 including thebearing portion 22B1 and a resin material as a second resin materialused for the movable member 21 including the electrode portion 21Ahaving the electroconductivity are a combination of the resin materialshaving no affinity for (compatibility with) each other.

A combination of the resin materials having affinity for each other is acombination of resin materials which melt in each other to form auniform state with no interface and which are the same material orcontain the same material component. The combination of the resinmaterials having no affinity for each other is a combination of resinmaterials which are easily separated from each other to form aninterface therebetween. For example, as one of the resin materials forthe movable member 21 and the supporting member 22, it is possible touse a polystyrene (PS)-based resin material widely used for the frame orparts. In this case, as the other resin material for the movable member21 or the supporting member 22, it is possible to use resin materials,having no affinity for the PS-based resin material, such aspolyoxymethylene (POM), polyamide (PA), polyethylene (PE), polypropylene(PP) and polyethylene terephthalate (PET).

In this embodiment, as the combination of the resin materials for thebearing 20, the PS-based resin material was used as the resin materialfor the supporting member 22, and POM having electroconductivity wasused as the resin material for the movable member 21. The resin materialhaving electroconductivity refers to a resin material having anelectrical conductivity of 10 Ω·cm or less as measured by a measuringmethod according to JIS K 7194, and the resin material having noelectroconductivity refers to a resin material having the electricalconductivity of more than 10 Ω·cm. In this way, by employing thecombination of the resin materials having no affinity for each other, amolded product formed of the first resin material is used as a mold, andthen the second resin material is injected into the mold, so that evenafter the second resin material is integrally molded with the firstresin material, the bearing portion 22B1 d and the shaft portion 21B areseparable at an interface therebetween. For this reason, it is possibleto form the movable member 21 including the electrode portion 21Arotatable about the shaft portion 21B relative to the base portion 22Aof the supporting member 22.

(Heat Conduction During Formation of Bearing)

Next, heat contraction during formation of the bearing 20 will bedescribed with reference to FIG. 10. In FIG. 10, (a) is a sectional viewof the neighborhood of the movable member 21 taken along B-B crosssection in (b) of FIG. 9 during the molding of the bearing 20. Further,(b) of FIG. 10 is a sectional view of the neighborhood of the movablemember 21 taken along the B-B cross section in (b) of FIG. 9 after themolding of the bearing 20. In FIG. 10, only a part of the mold forforming the shape of the movable member 21 is illustrated.

A dimensional relationship, by heat contraction, between the bearingportion 22B1 and the shaft portion 21B of the movable member 21 is asfollows. As shown in (a) of FIG. 10, the bearing portion 22B1 of theaccommodating portion 22B is molded early with the first resin material,and then the first resin material is cooled and solidified by a coolingstep in the member. Then, after the bearing portion 22B1 is molded, theelectroconductive resin material which is the second resin material isinjected into the bearing portion 22B1. This electroconductive resinmaterial is cooled and solidified from a state immediately after themolding as shown in (a) of FIG. 10 by a cooling step in the mold via thethird portion 22B1, so that the shaft portion 21B is molded. Further,the shaft portion 21B contracts as shown in (b) of FIG. 10 by beingcooled, so that a volume thereof decreases. For this reason, whentemperatures of the bearing portion 22B1 and the shaft portion 21Bbecome the substantially same, a gap is formed between the bearingportion 22B1 and the shaft portion 21B. That is, between the bearingportion 22B1 and the shaft portion 21B, a gap portion 20A which is spacewhere the electrode portion 21A is rotatable is formed. Accordingly, thebearing 20 is formed, in view of an operation (use) state after themolding, depending on coefficient of expansion of each of the first andsecond resin materials so that a diameter of the shaft portion 21B isprevented from becoming larger than a diameter of the bearing portion22B1 thereby to ensure the gap portion 20A. For this reason, e.g., atemperature of the bearing portion 22B1 during the molding is decreasedto a temperature lower than the lowest temperature estimated in anoperation environment after the molding, and thereafter the movablemember 21 including the shaft portion 21B is formed. As a result, themovable member 21 can be smoothly rotated about the bearing portion22B1.

(Effect of this Embodiment)

In the conventional constitution, the shaft was required to be moved tothe bearing portion along the slit, so that when a product requiringhigh accuracy was formed, it was difficult to dispose the rotatablemember with high accuracy.

In this regard, as described above, by employing the constitutionaccording to the present invention, it becomes possible to not onlysimplify the manufacturing step and the assembling step of the parts butalso dispose the movable member and the assembled connection part withhigh reliability, so that an assembling property of the cartridge can beimproved.

Specifically, in the conventional constitution, in the case where aplurality of parts were assembled and formed, in view of a dimensionalerror generating when individual parts were manufactured, size-adjustedparts were used. As a result, a yield in the assembling step is improvedand the assembling step can be simplified, whereas in the case ofincluding a movable part, between the movable part and another part, alarger gap (spacing) than is necessary was provided. Further, combinedwith a lowering in positional accuracy of the members generated in theassembling step, it was unable to dispose the movable part and theassembled part with high accuracy. In this regard, in this embodimentaccording to the present invention, by using the movable member 21formed by the injection molding so as to be movable relative to the baseportion 22A, it is possible to form the bearing 20 without providing thelarger gap than is necessary between the supporting member 22 and themovable member 21. Further, by providing the positioning portion, it ispossible to dispose the second frame 18 of the toner accommodatingcontainer 26 relative to the movable member 21 with high accuracy. Bythese constitutions, it is possible to realize a constitution in whichthe movable member 21 contacts the electrical contact portion 24A whichis the contact portion with high reliability. In this embodiment, theaccommodating portion 22B surrounding the movable member 21 is caused tofunction also as the positioning portion, so that positional accuracybetween the supporting member 22 and the movable member 21 can beenhanced.

In addition, in this embodiment, in order to use the movable member 21as the electrode, the electroconductive resin material was used. Theelectroconductive resin material used for the electrode portion 21A isprepared by dispersing, in a base material having noelectroconductivity, electroconductive particles such as carbon blackparticles or metal particles or electroconductive fibers such as carbonfibers, and therefore the electroconductive resin material hardens ingeneral, while being liable to fragile. For that reason, there is aliability that folding or the like occurs during the assembling of theelectrode portion 21A. Further, in the case where an electroconductiveresin sheet is used as the remaining amount detecting member 24, theelectrode portion 21A and the remaining amount detecting member 24 areassembled while contacting each other, and therefore there was aliability that abrasion or peeling of the electroconductive resin sheetgenerated. However, by employing the constitution according to thisembodiment, these liabilities can be eliminated.

Embodiment 2

In Embodiment 1, as the molded resin product used in the cartridgedetachably mountable to the image forming apparatus, the bearingincluding the electrode portion rotatable relative to the supportingmember was described. In this embodiment, as the molded resin product, abearing including an electrode portion slidable in a predetermineddirection relative to a supporting member will be described withreference to FIG. 11. Similarly as in the general structures of thecartridge and the image forming apparatus in Embodiment 1, the cartridgeas shown in FIG. 1 is used also in this embodiment and is constituted soas to be detachably mountable to the apparatus main assembly B as shownin FIG. 2.

(Structures of Bearing and Contact of Remaining Amount Detecting Member)

The bearing including the electrode will be described with reference toFIG. 11. In FIG. 11, (a) is a perspective view showing the bearing andan electrical contact of the remaining amount detecting member, and (b)is a sectional view showing the bearing and the electrical contact ofthe remaining amount detecting member taken along an axial direction ofthe developing roller.

As shown in (a) of FIG. 11, the remaining amount detecting member 24 ismounted on the second frame 18. Further, an electrical contact portion24A of the remaining amount detecting member 24 projects in one oflongitudinal sides of the toner accommodating container 26.Specifically, the electrical contact portion 24A is provided so as toproject into a bearing 30 connected to one of the first frame 17 (notshown) and the second frame 18. In this way, by providing the electricalcontact portion 24A of the remaining amount detecting member 24 at anoutside of a portion where the toner is accommodated, the electricalcontact portion 24A contacts an electrode portion 31A as a contactportion of a movable member 31, and thus is electrically connectedstably to the electrode portion 31A.

As shown in (b) of FIG. 11, the remaining amount detecting member 24 ismounted on the second frame 18 so that the electrical contact portion24A of the remaining amount detecting member 24 projects in one oflongitudinal sides of the toner accommodating container 26. Theelectrode portion 31A of the movable member 31 is provided on themovable member 31 of the bearing 30, and when the process cartridge ismounted in the apparatus main assembly B, a force is applied from theinputting portion 50 to the movable member 31, so that the movablemember 31 slides in an arrow F direction and thus the electrode portion31A is contactable to the electrical contact portion 24A of theremaining amount detecting member 24 with predetermined contactpressure. In this embodiment, a spring is used as an urging means 52,and when the cartridge A is mounted in a mounting position of theapparatus main assembly B, the electrical contact portion 24A is pressedby a force of about 120 gf exerted from the inputting portion 50 on theelectrode portion 31A. As a result, the electrical contact portion 24Aof the remaining amount detecting member 24 is electrically connected tothe inputting portion 50 via the electrode portion 31A of the bearing30. The urging means may also be an elastic member such as a rubber.

The electrical contact portion 24A of the remaining amount detectingmember 24 is, as shown in (a) of FIG. 11, provided on the surface of thesecond frame 18 outside the toner accommodating container 26 in one ofthe longitudinal sides of the toner accommodating container 26. In thiscase, the remaining amount detecting member 24 is formed with theelectroconductive resin sheet, so that the electrical contact portion24A is pulled out from the surface where the toner in the toneraccommodating container 26 exists to the surface of the second frame 18in an opposite side, and thus is exposed. Then, by sliding theelectrical contact portion 24A relative to the supporting member 32, theelectrode portion 31A is contacted to the exposed electrical contactportion 24A, so that the electrical contact portion 24A is electricallyconnected to the inputting portion 50.

As shown in (a) of FIG. 11, a constitution in which the electrodeportion 31A includes an electrode contact portion 31A1 which is a linearprojected portion having an arcuate cross section perpendicular to thelongitudinal direction was employed. The electrode contact portion 31A1extends in a direction crossing the arrow F direction, in the Figure,which is a movement direction (sliding direction) of the movable member31. On the other hand, the electrical contact portion 24A of theremaining amount detecting member 24 is constituted by a flat surfaceportion substantially perpendicular to the movement direction. For thisreason, the portion of contact between the electrode portion 31A and theelectrical contact portion 24A has a rectangular strip shape or a linearshape such that the electrode contact portion 31A1 which is the linearprojected portion and the electrical contact portion 24A which is theflat surface portion contact each other. As a result, compared with thecase where the flat surface portion of the electrode portion 31A and theflat surface portion of the electrical contact portion 24A are contactedto each other, a contact pressure per unit area can be increased, sothat electrical conduction between the electrode portion 31A and theelectrical contact portion 24A can be stably ensured. The structures ofthe electrode portion 31A and the electrical contact portion 24A are notlimited thereto, but it is also possible to employ the constitution inwhich these portions extend to one of the longitudinal sides of thetoner accommodating container 26 on the same plane similarly as in thecase of FIG. 6 and to employ a constitution in which the electrodeportion 31A is contacted to the electrical contact portion 24A as shownin (c) of FIG. 11.

(Structure of Bearing)

The bearing 30 including the electrode portion will be described withreference to FIGS. 12 and 13. FIG. 12 is a perspective view of thebearing 30. In FIG. 13, (a) to (c) are illustrations of the bearing 30,wherein (a) is the illustration showing the supporting member 32constituted by a base portion 32A, a positioning portion 32B and abearing portion 32C, and (b) and (c) are the illustrations showing themovable member 31.

In this embodiment as shown in FIG. 12, the bearing 30 is constituted bythe movable member 31 and the supporting member 32. The supportingmember 32 includes the base portion 32A including aportion-to-be-engaged 32D, the positioning portion 32B provided as apart of the base portion 32A, and the bearing portion 32C. Thepositioning portion 32B is provided behind the base portion 32A asindicated by a broken line in FIG. 12 and is not visible in actuality.On the other hand, the movable member 31 includes the electrode portion31A and an engaging portion 31B connected to the electrode portion 31A.

The engaging portion 31B engages with the portion-to-be-engaged 32D viaa gap portion described later, so that the movable member 31 is slidablein the arrow F direction relative to the base portion 32A. Specifically,as shown in FIG. 13, the portion-to-be-engaged 32D is provided with alimiting (regulating portion) 32D1 having a linear projected shape, andthe limiting portion 32D1 is engaged with a supporting portion 31B1,having a groove shape, of the engaging portion 31B. As a result, themovable member 31 is supported slidably in the arrow F directionrelative to the base portion 32A. Further, in one side with respect tothe arrow F direction, the portion-to-be-engaged 32D is provided with apreventing portion 32D2, and the preventing portion 32D2 is contacted toa retaining portion 31B2 of the engaging portion 31B. The preventingportion 32D2 is disposed so as to contact at least the retaining portion31B2, so that in the case where the movable member 31 slides toward theone side in the arrow F direction, the movable member 31 is preventedfrom being detached from the supporting member 22. That is, in thisembodiment, a constitution in which the movable member 31 is notdetached from the supporting member 32 is employed. A portion where themovable member 31 is surrounded by the base portion 32A has such a shapethat a width thereof increases from one end side toward the other endside ((a) of FIG. 14), and the movable member 31 is movable relative tothe base portion 32A from one end side toward the other end side.

In this embodiment, the positioning portion 32B is provided as a part ofthe base portion 32A. By the positioning portion 32B, the electricalcontact portion 24A of the remaining amount detecting member 24positions the electrode portion 31A relative to each other when themovable member 31 is moved, so that the supporting member 32 and thesecond frame 18 of the toner accommodating container 26 can be disposedat a contactable position. Specifically, in this embodiment, aportion-to-be-positioned 24B is provided on a side wall portion,provided on the second frame 18, indicated by a broken line in (a) ofFIG. 11. On the other hand, the positioning portion 32B is, as indicatedby a broken line in FIG. 13, provided on the surface of the base portion32A toward an arrow E4 direction. By engaging theportion-to-be-positioned 24B and the positioning portion 32B, thepositioning is made. The present invention is not limited to thisconstitution, but may also employ a constitution in which when themovable member 31 is moved, the electrical contact portion 24A of theremaining amount detecting member 24 can be disposed at a contactableposition with the electrode portion 31A.

(Bearing Molding Method)

A molding method of the bearing 30 will be described with reference toFIGS. 13 and 14. In FIG. 14, (a) is a front view of the bearing 30, and(b) is a sectional view, taken along C-C line in (a) of FIG. 14, showingthe neighborhood of the movable member 31 of the bearing 30.

Of the bearing 30, the supporting member 32 constituted by the baseportion 32A, the positioning portion 32B and the bearing portion 32C isformed early. During molding, the mold is opened toward at least one ofan arrow E3 direction and the arrow E4 direction. In this embodiment,the arrow E3 direction side is a cavity side (fixed side) and the arrowE4 direction side is a core side (movable side), and a constitution inwhich the core is moved in the arrow E4 direction to open the mold wasemployed. However, the arrow E3 direction side is the core side (movableside) and the arrow E4 direction side is the cavity side (fixed side),and a constitution in which the core is moved in the arrow E3 directionto open the mold may also be employed.

Thereafter, the movable member 31 as shown in (b) of FIG. 13 isintegrally molded with the supporting member 32, so that the bearing 30is formed. At this time, molds 29A and 29B as shown in FIG. 14 areprovided as separate members from a mold for the supporting member 32 inorder to form a shape of the movable member 31. As a structure of themolds, a structure in which the cavity-side mold 29A is used as a moldcommon to the supporting member 22 and the movable member 31 and onlythe core-side mold is different from the cavity-side mold 29A may alsobe employed. Further, as shown in (b) of FIG. 14, after the supportingmember 32 is formed, a part 29B1 of the core-side mold 29B in a regionsuperposed on or adjacent to the portion-to-be-engaged 32D is moved inthe arrow E4 direction which is a member-opening direction, and may alsobe used as a mold for forming the movable member 31. In this way, thepart 29B1 of the cavity-side mold 29B superposed on theportion-to-be-engaged 32D is moved in the arrow E4 direction, so that aspace for forming the portion-to-be-engaged 32D can be provided.Further, the movable member 31 is molded by injecting anelectroconductive resin material into a space formed between thesupporting member 32 and the molds 29A and 29B. For that reason, theengaging portion 31B of the movable member 31 is formed in such a shapethat a shape of the portion-to-be-engaged 32D is transferred.

In this way, a contact interface is formed between the moldedportion-to-be-engaged 32D and the engaging portion 31B. Further, alsoother than the contact interface between the portion-to-be-engaged 32Dand the engaging portion 31B, a contact interface is formed between thebase portion 32A and the movable member 31 formed between the baseportion 21A and the molds 29A and 29B. In this way, between the movablemember 31 and the supporting member 32, the interfaces are formed, sothat the engaging portion 31B is engaged with the portion-to-be-engaged32D to guide the movable member 31, thus permitting movement of themovable member 31 in the arrow F direction which is the movementdirection.

Also in this embodiment, similarly as in Embodiment 1, it is preferablethat a first resin material used as a resin material for the supportingmember 32 including the portion-to-be-engaged 32D and a second resinmaterial used as a resin material for the movable member 31 are acombination of the resin materials having no affinity for (compatibilitywith) each other. As a result, the movable member 31 and the supportingmember 32 are separable at the interface, so that the engaging portion31B is slidable with the portion-to-be-engaged 32D.

(Heat Conduction During Formation of Bearing)

Next, an influence of heat contraction during formation of the bearing30 will be described with reference to FIG. 15. In FIG. 15, (a) to (c)are sectional views of the neighborhood of the engaging portion 31B andthe portion-to-be-engaged 32D of the bearing 30 shown in (b) of FIG. 14.In FIG. 15, (a) is the sectional view of C-C cross section of (a) ofFIG. 14, (b) is the sectional view of D-D cross section of (a) of FIG.14, and (c) is an illustration showing a state in which the movablemember 31 is moved from a position of (b) of FIG. 15 in the arrow Fdirection.

A dimensional relationship, by heat contraction, between theportion-to-be-engaged 32D of the supporting member 32 and the engagingportion 31B of the movable member 31 is as follows. Theportion-to-be-engaged 32D of the supporting member 32 is molded earlywith the first resin material, and then the first resin material iscooled and solidified by a cooling step in the member. Then, after theportion-to-be-engaged 32D is molded, the electroconductive resinmaterial which is the second resin material is injected into a spaceformed between the supporting member 32 including theportion-to-be-engaged 32D and the molds 29A and 29B. Thiselectroconductive resin material is cooled and solidified from a stateimmediately after the molding as shown in (a) and (b) of FIG. 15 by acooling step in the mold via the portion-to-be-engaged 32D and the like,so that the engaging portion 31B is molded.

At this time, the engaging portion 31B contracts by being cooled, sothat a force is applied in a direction in which theportion-to-be-engaged 32D is compressed. As a result, a frictional forcebecomes large at the interface between the portion-to-be-engaged 32D andthe engaging portion 31B, so that smooth sliding of the movable member31 with the supporting member 32 is prevented. Therefore, as shown in(a) of FIG. 15, with respect to a direction in which theportion-to-be-engaged 32D is sandwiched by the engaging portion 31B,compared with one end side of the arrow F direction in which the movablemember 31 slides, a thickness of the movable member 31 in the other endside is made thin.

Specifically, the limiting portion 32D1 sandwiched by the supportingportion 31B1 is formed so that surfaces which incline in the arrow E3direction and the arrow E4 direction, respectively, with respect to thearrow H direction which crosses the arrow F direction and in which thesupporting portion 31B1 sandwiches the limiting portion 32D1 oppose eachother. Each of the surfaces, of the portion-to-be-engaged 32D, eachinclining with respect to the arrow H direction may preferably have aninclination angle φ of 5° or more with respect to the arrow H direction.As a result, irrespective of the influence of the contraction by heat,the movable member 31 can be made smoothly slidable with the supportingmember 32. On the other hand, as shown in FIG. 14, the movable member 31is formed so as to be sandwiched by the base portion 32A with respect tothe arrow H direction and has such a shape that the width of the movablemember 31 with respect to the arrow H direction increases from one endside toward the other end side with respect to the arrow F direction. Asa result, when the movable member 31 moves from one end side toward theother end side, with respect to the arrow H direction, a gap (spacing)30A is formed between the base portion 32A and the movable member 31including between the preventing portion 32D2 and the retaining portion31B2.

Similarly, as shown in (b) of FIG. 15, the preventing portion 32D2sandwiched by the retaining portion 31B is formed so that surfaces whichincline in the arrow E3 direction and the arrow E4 direction,respectively, with respect to the arrow F direction oppose each other.Each of the surfaces inclining with respect to the arrow F direction maypreferably have an inclination angle θ of 5° or more with respect to thearrow F direction. As a result, when the movable member 31 is moved fromone end side to the other end side, as shown in (c) of FIG. 15, the gap30A is formed between the preventing portion 32D2 and the retainingportion 31B2. As a result of these, irrespective of the influence of thecontraction by heat, the movable member 31 can be made smoothly slidablewith the supporting member 32.

In this way, the engaging portion 31B is constituted so that a bottomthereof opposing the opening has a cross section having a recessed shapenarrower than the opening, so that the portion-to-be-engaged 32D isprevented from engaging with the engaging portion 31B, thus beingprevented from becoming immovable. Further, one or both of the opposingsurfaces in the recessed shape are constituted so as to be in parallelto the arrow F direction which is the movement direction, so that themovable member 31 is moved thereby to form the gap 30A between the baseportion 32A and the movable member 31, and thus it is possible tosmoothly slide the movable member 31.

(Effect of this Embodiment)

As described above, similarly as in Embodiment 1, by employing theconstitution according to the present invention, it becomes possible tonot only simplify the manufacturing step and the assembling step of theparts but also dispose the movable member and the assembled connectionpart with high reliability, so that an assembling property of thecartridge can be improved.

Specifically, by using the movable member 31 formed by the injectionmolding so as to be movable relative to the base portion 32A, it ispossible to form the bearing 30 without providing the larger gap than isnecessary between the supporting member 32 and the movable member 31.Further, by providing the positioning portion, it is possible to disposethe second frame 18 of the toner accommodating container 26 with highaccuracy. By these constitutions, it is possible to realize aconstitution in which the movable member 31 contacts the electricalcontact portion 24A which is the contact portion with high reliability.

In addition, in this embodiment, in order to use the movable member 31as the electrode, the electroconductive resin material was used. Theelectroconductive resin material used for the electrode portion 31A isprepared by dispersing, in a base material having noelectroconductivity, electroconductive particles such as carbon blackparticles or metal particles or electroconductive fibers such as carbonfibers, and therefore the electroconductive resin material hardens ingeneral, while being liable to fragile. For that reason, there is aliability that folding or the like occurs during the assembling of theelectrode portion 31A. Further, in the case where an electroconductiveresin sheet is used as the remaining amount detecting member 24, theelectrode portion 31A and the remaining amount detecting member 24 areassembled while contacting each other, and therefore there was aliability that abrasion or peeling of the electroconductive resin sheetgenerated. However, by employing the constitution according to thisembodiment, these liabilities can be eliminated.

Embodiment 3

In Embodiment 2, as the molded resin product, the bearing including theelectrode portion slidable with the supporting member in thepredetermined was described. In this embodiment, another constitution inwhich it is possible to stably ensure electrical conduction between anelectrode portion of a bearing and an electrical contact portion will bedescribed.

An outline of a cartridge and an image forming apparatus used in thisembodiment is similar to that described in Embodiment 1. Further, astructure of the bearing, a sliding structure of a movable member and amolding method of the bearing are similar to those described inEmbodiment 2. In the following, constituent elements similar to those inEmbodiments 1 and 2 are represented by the same reference numerals orsymbols and will be omitted from description, and a difference will beprincipally described.

(Structure of Developing Unit)

First, a structure of a developing unit 38 used in this embodiment willbe described with reference to FIG. 16. FIG. 16 is a perspective view ofthe developing unit 38.

Similarly as in Embodiment 1, at longitudinal ends of the toneraccommodating container 26, bearings 63 and 67 are provided. The bearing63 is positioned relative to an unshown positioning portion provided ona second frame 62 by positioning portions 64B provided at two positionson a base portion 64A of a supporting member 64, and is connected to thesecond frame 62. The bearing 63 includes a movable member 65 and afixing member 66 which are each formed of an electroconductive resinmaterial. The developing roller 13 is rotatably supported by the bearing67 in one end side and by the fixing member 66, formed as a part of thebearing 63, in the other end side.

(Structure of Bearing)

Next, the bearing used in this embodiment will be described. A structureof the bearing 67 in one end side is similar to that in Embodiment 1. Inthis embodiment, the bearing 63 in the other end side will be describedwill be specifically described with reference to FIGS. 17 and 18. InFIG. 17, (a) to (c) are schematic views for illustrating the bearing 63,wherein (a) is a perspective view of an inside of the bearing 63 as seenfrom obliquely above the bearing 63, and (b) and (c) are perspectiveviews of the movable member 65 and the fixing member 66, respectively.FIG. 8 is a perspective view of an outside of the bearing 63 as seenfrom obliquely below the bearing 63.

As shown in FIG. 17, the bearing 63 includes the supporting member 64,the movable member 65 and the fixing member 66. The movable member 65has the slidable constitution in the arrow F direction in the figuresimilarly as in Embodiment 2, and also the forming method thereof issimilar to that in Embodiment 2. An electrode portion 65A of the movablemember 65 is provided with a portion-to-be-contacted (electrode contactportion) 65A1 which is an electrical contact portion with a detectingmember 70 (FIG. 19) of a second frame 62 described later.

On the other hand, the fixing member 66 is provided with a developingcontact portion 66A which is an electrical contact portion for receivinga developing bias supplied from the apparatus main assembly and providedwith a bearing portion 66B which is a supporting portion for thedeveloping roller 13. In (b) and (c) of FIG. 17, states of only themovable member 65 and the fixing member 66, respectively, areillustrated, but these two members are formed of the electroconductiveresin material and are integrally molded with the supporting member 64.The forming methods of these members are similar to those in Embodiment2. The developing contact portion 66A and the bearing portion 66B of thefixing member 66 are integrally formed of the electroconductive resinmaterial, and therefore are capable of supplying the developing bias, tothe developing roller, supplied from an electrical contact portionsurface 66A1 shown in FIG. 18.

(Structure of Contact of Remaining Amount Detecting Portion)

A structure of the second frame 62 will be described with reference toFIGS. 19 and 20. In FIG. 19, (a) and (b) show the second frame 18,wherein (a) is a perspective view of the second frame 18 as seen fromobliquely above, and (b) is a perspective view of the second frame 18 asseen from obliquely below. FIG. 20 is a sectional view of J-J crosssection in (a) of FIG. 19.

As shown in (a) of FIG. 19, similarly as in Embodiment 1, the secondframe 62 is provided with a remaining amount detecting member 70 so asto be positioned inside a toner accommodating container 60. Theremaining amount detecting member 70 is formed with theelectroconductive resin sheet, and in this embodiment, is formed byinsert molding, so that the remaining amount detecting member 70 isformed integrally with the second frame 62.

Further, the second frame 62 is provided with an electrical contactportion 62A at a longitudinal end portion in the bearing 67 side whichis one end side. As shown in (b) of FIG. 19, at this electrical contactportion 62A, the remaining amount detecting member 70 is formed so as tobe positioned on an outer surface of the toner accommodating container60. That is, as shown in FIG. 20, the remaining amount detecting member70 is constituted so as to be exposed to the outer surface side via apenetrating portion q penetrating from an inside to the outer surfaceside of the toner accommodating container 60.

As shown in FIG. 20, the electrical contact portion 62A is constitutedby a flat surface portion 62A1 which is a surface perpendicular to amovement direction F of the movable member 65 and an inclined surface65A2 providing an angle θ1 with respect to the flat surface portion62A1. The angle θ1 formed between the flat surface portion 62A1 and theinclined surface 62A2 is an obtuse angle, i.e., θ1<180°. The remainingamount detecting member 70 is disposed along a surface cured withrespect to a direction crossing the longitudinal direction over a regionfrom the flat surface portion 62A1 to the inclined surface 62A2, andincludes an edge line portion 70A. Although specifically describedlater, this edge line portion 70A is an electrical contact portion withthe movable member 65.

Next, a constitution of a state in which the bearing 63 is connected tothe toner accommodating container 60 will be described with reference toFIGS. 21 and 22. In FIG. 21, (a) and (b) are sectional views of K-Kcross section in FIG. 16, wherein (a) shows a state in which the movablemember 65 is spaced from the electrical contact portion 62A of thesecond frame 62, and (b) shows a state in which the movable member 65 iscontacted to the electrical contact portion 62A of the second frame 62.FIG. 22 is an illustration of the electrical contact portion 62A of thesecond frame 62 as seen from a movable member side.

Similarly as in Embodiment 2, as shown in (b) of FIG. 21, a limitingportion of the supporting member 64 and a groove-shaped supportingportion 65B1 of the movable member 65 engage with each other, so thatthe movable member 65 is slidable along a line L parallel to themovement direction F. As shown in (a) of FIG. 21, the movable member 65has a constitution for permitting movement thereof by a distance d1 of agap provided between itself and the supporting member 64. Further, whenthe cartridge A is mounted in the apparatus main assembly B, as shown in(b) of FIG. 21, the electrical contact portion 65A2 is pressed by theinputting portion 51 which is a main assembly-side electrical contactmember, s that the movable member 65 is moved upward in the arrow Fdirection in the figure. As a result, the surface curved with respect tothe direction crossing the longitudinal direction and the movable member65, specifically the edge line portion 70A of the remaining amountdetecting member 70 and the movable member 65 contact each other.

As shown in FIG. 17, the electrode contact portion 65A1 of the movablemember 65 has a cross section, perpendicular to the longitudinaldirection, constituting a linear projected portion having an arcuateshape. Further, as shown in (a) of FIG. 21, the electrode contactportion 65A1 is constituted so that a projection amount from a surface65A3 of the electrode portion 65A perpendicular to the movementdirection F of the movable member 65 increases toward a longitudinal endportion and so that the electrode contact portion 65A1 inclines withrespect to the longitudinal direction with an angle θ2.

Further, the remaining amount detecting member 70 and the movable member65 are disposed so that in a contact state ((b) of FIG. 21), theelectrode 65A1 and the flat surface portion 62A1 provide a certain angleθ3 and the electrode contact portion 65A1 and the inclined surface 62A2provide a certain angle θ4. In this embodiment, both the flat surfaceportion 62A1 of the second frame 62 and the surface 65A3 of theelectrode portion 65A of the movable member 65 are surfaces (planes)extending in the longitudinal direction, and therefore are constitutedso that the angle θ2 and the angle θ3 are the same angle.

Further, as shown in FIG. 22, the electrode contact portion 65A1 extendsin a direction substantially perpendicular to the edge line portion 70Aprovided at the electrical contact portion 62A of the second frame 62.By employing the above-described constitution, the movable member 65 andthe remaining amount detecting member 70 contacts only at a pint p. Inthis embodiment, the electrode contact portion 65A1 and the edge lineportion 70A provided at the electrical contact portion 62A of the secondframe 62 are substantially perpendicular to each other, but arecontactable to each other only at the point p if these portions crosseach other.

In this embodiment, the portion of contact between the movable member 65and the remaining amount detecting member 70 was constituted as arectilinear portion, so that a point contact was realized. As a result,an urging force from the inputting portion 51 is concentrated, so that acontact pressure per unit area can be further increased, and thereforeelectrical conduction between the remaining amount detecting member 70of the electrical contact portion 62A and the electrode portion 65A ofthe movable member 65 which are constituted by the electroconductiveresin materials can be stably ensured.

Further, the movable member 65 has a distance d2 (<d1) in a gap with thesupporting member 64 in a contact state ((b) of FIG. 21). As a result, aconstitution in which a portion, of the movable member 65, other thanthe electrical contact portion is prevented from contacting thesupporting member 64 with respect to a movable direction (arrow Fdirection in the figure) and the contact pressure between the movablemember 65 and the remaining amount detecting member 70 can be furtherenhanced using the urging force from the inputting portion 51 isemployed.

As shown in (a) of FIG. 23, the inputting portion 51 which is an urgingmember is disposed inside a portion of contact (rectilinear line L in(a) of FIG. 23) between the movable member 65 and the limiting portionand the preventing portion 64D2 of the supporting member 64 with respectto the longitudinal direction. For this reason, moment Ml shown in (a)of FIG. 23 acts on the movable member 65. As a result, the movablemember 65 is contacted to the remaining amount detecting member 70 bythe moment M1 while inclining in an arrow N1 direction (clockwise) in arange of a gap (spacing) 30A. Specifically, as described in Embodiment2, the movable member 65 forms the gap 30A or the like ((c) of FIG. 15)when moved in the movable direction (arrow F direction in the figure).For this reason, a constitution in which an angle α formed between theline L parallel to the movement direction F and an extension directionof the groove-shaped supporting portion 65B1 of the movable member 65 inthe range of the gap 30A does not become zero, and thus the movablemember 65 can be slightly inclined is employed. Therefore, in thisembodiment, α<θ3 is satisfied, so that the movable member 65 and theelectrical contact portion 62A are constituted so that the contacttherebetween is maintained at only the point p.

Further, due to deformation or the like of the inputting portion 51, asshown in (b) of FIG. 23, in the case where the inputting portion 51which is an urging member is disposed outside a portion of contactbetween the movable member 65 and the limiting portion and thepreventing portion 64D2 of the supporting member 64 with respect to thelongitudinal direction, moment M2 shown in (b) of FIG. 23 acts on themovable member 65. As a result, the movable member 65 is inclined in anarrow N2 direction (counterclockwise) by the moment M2. Specifically, anangle β formed between the line L parallel to the movement direction Fand an extension direction of the groove-shaped supporting portion 65B1of the movable member 65 in the range of the gap 30A does not becomezero, and thus the movable member 65 can be slightly inclined.Therefore, in this embodiment, β<θ4 is satisfied, so that the movablemember 65 and the electrical contact portion 62A are constituted so thatthe contact therebetween is maintained at only the point p.

Next, with reference to FIG. 24, a constitution of assembling of thebearing 63 with the toner accommodating container 60 will be described.FIG. 24 shows a state before the bearing 63 is mounted on the toneraccommodating container 60 and is a sectional view of K-K cross sectionin FIG. 16. Similarly as in Embodiment 2, the bearing 63 is assembled ina state in which a positioning portion 64B (FIG. 17) is positioned to aportion-to-be-positioned of the toner accommodating container 60. Thatis, as shown in FIG. 24, the bearing 63 is assembled with respect to thearrow N direction in the figure in a state in which the bearing 63 ispositioned relative to the toner accommodating container 60 with respectto a short direction (perpendicular to the longitudinal direction).During this assembling, the movable member 65 is constituted so that anend portion 65A4 thereof and a free end 62A3 of the electrical contactportion 62A do not run against each other even in a state in which themovable member 65 abuts against the supporting member 64 at an upperside of the movable direction (arrow F direction), i.e., even in a statein which a gap d3 is zero. That is, with respect to an assemblingdirection (longitudinal direction of the developing unit) of the bearing63, the outside end portion 65A4 of the electrode contact portion 65A1is formed so as to be positioned below a central end portion 62A3 of theelectrical contact portion 62A provided as a part of the second frame62. In this way, during the assembling, in the movable range of themovable member 65, a constitution in which the end portion 65A4 of themovable member 65 and the free end 62A3 of the electrical contactportion 62A do not run against each other is employed, so that breakageor the like is prevented.

(Effect in this Embodiment)

As described above, in this embodiment, the electrode contact portion65A1 increased in projection amount toward the longitudinal end portionwas provided as a part of the movable member, and the electrical contactportion 62A of the remaining amount detecting member 70 was formed atthe surface curved with respect to the direction crossing thelongitudinal direction. Further, the electrode contact portion 65A1 andthe electrical contact portion 62A formed at the surface curved withrespect to the direction crossing the longitudinal direction arecontacted to each other, so that the contact pressure per unit area canbe enhanced and thus the electrical conduction between the electrodeportion of the bearing and the electrical contact portion can be stablyensured. This constitution is particularly effective in the case wherethe electrode portion of the bearing and the electrical contact portionare formed of the electroconductive resin material. Further, theelectrode contact portion 65A1 was formed as the linear projectedportion, of the movable member 65, where the projection amount increasedtoward the longitudinal end portion. As a result, in the case where themovable member 65 is prepared as a part of the bearing 63 by injectionmolding, by using a drawing slope used for parting the mold, a shape ofthe movable member 65 can be easily formed.

Further, in this embodiment, in consideration of a slope of the movablemember 65 by the longitudinal position of the inputting portion 51, theangle θ3 (angle formed between the electrode contact portion 65A1 andthe flat surface portion 62A1) and the angle θ4 (angle formed betweenthe electrode contact portion 65A1 and the inclined surface 62A2) wereset. As a result, the electrical conduction can be stably ensured evenin the case where the contact position of the inputting portion 51 withthe movable member 65 fluctuates due to deformation or the like of theinputting portion 51, e.g., during transportation in the case where thecartridge A is mounted and packed in the apparatus main assembly B.

Further, in this embodiment, the positioning is made by the positioningportion 64B and the portion-to-be-positioned of the toner accommodatingcontainer 60, so that the bearing 63 and the second frame 62 areintegrated with each other. At this time, a constitution in which evenin the state the movable member 65 runs against the supporting member64, the end portion 65A4 of the movable member 65 and the free end 62A3of the electrical contact portion 62A are prevented from running againsteach other is employed. As a result, a constitution in which the endportion 65A4 of the movable member 65 and the free end 62A3 of theelectrical contact portion 62A are prevented from running against eachother in the movable range of the movable member 65 during theassembling is employed, so that breakage or the like can be prevented.

In this embodiment, the electrode contact portion 65A1 of the movablemember 65 was formed as the linear projected portion which had anarcuate shape in cross section perpendicular to the longitudinaldirection and which was increased in projection amount toward thelongitudinal end portion as shown in (a) of FIG. 25. However, as amodified embodiment, a constitution in which a simple projected portionis provided or a constitution in which as in a movable member 71 shownin (b) of FIG. 25, an electrode contact portion 71A consisting of alinear projected portion which has a triangular shape in cross sectionperpendicular to the longitudinal direction and which has a projectionamount unchanged over the longitudinal direction is provided may also beemployed. Alternatively, a constitution in which as in a movable member72 shown in (c) of FIG. 25, an electrode contact portion 72A consistingof a linear projected portion which has a triangular shape in crosssection perpendicular to the longitudinal direction and which increasesin projection amount toward the longitudinal end portion is provided orthe like constitution may also be employed.

Other Embodiments

In the above-described embodiments, as the molded resin product, thebearing including the movable member rotatable relative to thesupporting member and the bearing including the movable member slidablewith the supporting member were described. However, the presentinvention is not limited, but as shown in FIG. 26, a constitution inwhich a plurality of movable members 42 and 43 are provided for asupporting member 41 may also be employed. In this case, a relation anda constitution of the supporting member 41 and the movable member 42 areconstituted similarly as in Embodiment 1, so that the movable member 42is rotatable in an arrow G direction. Further, a relation and aconstitution of the supporting member 41 and the movable member 43 areconstituted similarly as in Embodiment 2, so that the movable member 43is slidable in an arrow F direction.

In the above-described embodiments, the case where the electroconductiveresin material is used for the movable member, but the present inventionis not limited thereto, and an insulative resin material may also beused.

While the invention has been described with reference to the structuresdisclosed herein, it is not confined to the details set forth and thisapplication is intended to cover such modifications or changes as maycome within the purpose of the improvements or the scope of thefollowing claims.

This application claims the benefit of Japanese Patent Application Nos.2014-084038 filed on Apr. 15, 2014 and 2015-021651 filed Feb. 5, 2015,which are hereby incorporated by reference herein in their entirety.

1-35. (canceled)
 36. A method of manufacturing a movable member for usewith an image forming apparatus, the movable member including anengaging portion and the movable member being movable with a supportingmember, the manufacturing method comprising: a step of injecting a resinmaterial into a space formed by the supporting member and a mold so thatthe movable member is formed; and a step of cooling the resin materialso as to shrink the resin material and thereby form a gap between theengaging portion and a portion-to-be-engaged of the supporting portion.37. A manufacturing method according to claim 36, wherein the engagingportion has a bearing portion, the portion-to-be-engaged is a shaft thatis supported by the bearing portion, and the gap formed in the coolingstep is between the bearing portion and the shaft, thereby making themovable member rotatable relative to the supporting member.
 38. Amanufacturing method according to claim 36, wherein the engaging portionhas a groove and the gap formed in the cooling step is between thegroove and the portion-to-be-engaged, thereby making the movable memberslidable relative to the supporting member.
 39. A manufacturing methodaccording to claim 38, wherein the engaging portion is formed so as tohave a cross section including a recess-shaped portion having a bottomthat opposes an opening through which the portion-to-be-engaged enters,with the bottom being narrower than the opening.
 40. A manufacturingmethod according to claim 39, wherein the recess-shaped portion hasopposing surfaces formed non-parallel with a movement direction of themovable member.
 41. A manufacturing method according to claim 36,wherein the resin material is a first resin material havingelectroconductivity, the supporting member is formed by a second resinmaterial that has no electroconductivity, and the first resin materialand the second resin material have no affinity.
 42. A manufacturingmethod according to claim 36, wherein the movable member includes anelectrode portion.
 43. A method of manufacturing a cartridge that isdetachably mountable to an image forming apparatus, the cartridgeincluding a movable member, with the movable member including anengaging portion and being movable with a supporting member, themanufacturing method comprising: a step of injecting a resin materialinto a space formed by the supporting member and a mold so that themovable member is formed; and a step of cooling the resin material so asto shrink the resin material and thereby form a gap between the engagingportion and a portion-to-be-engaged of the supporting portion.
 44. Amanufacturing method according to claim 43, wherein the engaging portionhas a bearing portion, the portion-to-be-engaged is a shaft that issupported by the bearing portion, and the gap formed in the cooling stepis between the bearing portion and the shaft, thereby making the movablemember rotatable relative to the supporting member.
 45. A manufacturingmethod according to claim 42, wherein the engaging portion has a grooveand the gap formed in the cooling step is between the groove and theportion-to-be-engaged, thereby making the movable member slidablerelative to the supporting member.
 46. A manufacturing method accordingto claim 45, wherein the engaging portion is formed so as to have across section including a recess-shaped portion having a bottom thatopposes an opening through which the portion-to-be-engaged enters, withthe bottom being narrower than the opening.
 47. A manufacturing methodaccording to claim 46, wherein the recess-shaped portion has opposingsurfaces formed non-parallel with a movement direction of the movablemember.
 48. A manufacturing method according to claim 43, wherein theresin material is a first resin material having electroconductivity, thesupporting member is formed by a second resin material that has noelectroconductivity, and the first resin material and the second resinmaterial have no affinity.
 49. A manufacturing method according to claim43, wherein the movable member includes an electrode portion.